The History and Natural History of Dengue Fever

The exact origins of the disease are not clear and arguments have been made that it

originated in Africa and was spread worldwide with the slave trade. The most convincing

explanation for the name dengue is that it is derived from the Swahili "Ka-Dinga pepo" that

describes the disease as a sudden cramp like disease caused by an evil spirit. It has also

been argued that it originated in the Malay Peninsula of Indochina. Regardless, in the wild

the virus has a life cycle very similar to that of yellow fever involving passing between

primates living in the jungle canopy and mosquitoes that feed on them. It is believed that

the virus was transferred to man by the bite of the tiger-striped mosquito (Aedes albopticus)

as man began clearing the jungle and building settlements. The commonest vector is now

the closely-related mosquito Aedes aegypti which is African in origin but has spread

throughout the tropics in the Old and New Worlds.

The earliest reports of a dengue-like disease are from Chin Dynasty China (265-420 AD).

The first rigorously documented outbreaks occurred almost simultaneously in:

Cairo and Alexandria (Egypt, 1799);

Jakarta (the called Batavia, Indonesia, 1799);

Philadelphia (United States, 1780);

Madras (India, 1780).

Outbreaks have occurred throughout the temperate and tropical climes since then.

The virus was identified in the 1940's when it became a concern to the armies fighting in

Pacific and Asia as it was causing a large number of non-combat casualties to Allied and

Japanese forces. Japanese scientists first identified the virus in 1943 and were quickly

followed by U.S. researchers. By 1956 the four serotypes of the virus were identified and

every outbreak of the disease since has been due to a virus belonging to one of the four

serotypes.

Work is being done on the development of vaccines against the disease but there are

currently none proven safe and effective for human use. The primary method of preventing

the spread of the disease is by controlling the mosquito vectors and this has proven

effective and the disease appeared to be on the decline for many years, however it had a

resurgence in the 1990's and remains a major public health problem in many areas and the

current situation has been designated a global pandemic.

The most worrisome aspect of the resurgence is that it has come with an increase in the

frequency and severity of dengue hemorrhagic syndrome, a severe complication of the

disease normally only arising upon re-infection. Typically, when diseases first crossover to

man they are at their most severe (syphilis is the prime example of this) and over the years

they become less severe as they adapt themselves to a new host. Dengue appears to be

running against the stream, making it a greater public health and weapons threat.

Take of: http://www.cbwinfo.com/Biological/Pathogens/DENV.html